Decca Tree
From WikiRecording
The Decca Tree mike technique employs three usually omnidirectional microphones placed in a triangle, with one microphone in front closer to the sound source. Decca Tree is most popular for orchestral and large string section recordings in large acoustically designed rooms or halls and is commonly used in Hollywood film soundtracks. The advantages of the Decca Tree are similar to the MS mic technique over AB in the fact that you have the ability to adjust the center microphone thus adjusting the power and central pull of the sound. AB Stereo Microphone Technique is sometimes criticized for lacking a central pull and being too wide a stereo image when placed close to a sound source. The Decca Tree began as a modified AB adding the center forward spaced microphone. Original size of the "T" or "Triangle" was 2 meters wide and 1.5 meters deep.
History: The Decca Tree technique first came out of Decca Records studio's and there research and experimentation in stereo techniques in the mid 50's. Engineer Roy Wallace with Arthur Haddy, Kenneth Wilkinson, Stan Goodall were the first to construct and demonstrate the effects of the tree. Over the years different microphones have been used including Omnidirectional and Cardioide patterns. Some of the original microphones used were Neumann KM56, M201, M49, KM53, and the M50.
Setup: This depends greatly on the size and characteristic of the room, as well as the size of the orchestra/choir etc. However in general the microphones are spaced a few feet apart in T/Triangle facing the sound source (facing in the sense of (one corner/bottom of T) pointing towards the musicians). Decca Tree was originally setup using a metal t structure. The "T" support originally measured 2 meters wide by 1.5 meters deep.
Links/Sources:
- See more pictures of the Decca Tree used for an orchestra at Abbey Road Studio 1
- Short article on decca tree recording
- Mix Online's overview including recent adaptations of Decca Tree for Surround
- Decca Tree Recording with Georg Neumann pressure microphones M 50 - in German — pdf
- wikipedia article
- Webpage on Decca Tree
- The Decca Tree — It's not just for stereo any more — pdf
- A Decca Tree primer — Wes Doley, Audio Engineering Associates AEA — pdf
- Stereo Bars and Decca Trees — Wes Dooley, Audio Engineering Associates AEA — pdf
